Thread protector

ABSTRACT

A thread protector for protecting threads on the end of a pipe includes a base portion, a threaded portion extending axially from a first end of the base portion and threadably engageable with the pipe and an elongated annular bumper extending axially from a second end of the base portion. The elongated bumper has an average length and width such that the ratio of the length to the width is at least 2. The base and elongated bumper have a total length of at least two inches.

RELATED APPLICATION

The present application claims the benefit of 35 U.S.C. §111(b)provisional application Ser. No. 60/086,446 filed May 22, 1998, and acontinuation of 35 U.S.C. §120 utility application Ser. No. 09/315,865filed May 20, 1999 now U.S. Pat. No. 6,196,270, each of which is herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to protectors for protecting the ends of pipe, andparticularly for protecting the threads on the ends of pipe.

Pipes, such as pipes used for oil and gas drilling and production, areoften produced in sections and are connectable at their ends. One typeof connection involves the use of a male threaded portion at one end(the pin end) of a section of pipe that is threadingly engageable with afemale threaded portion at the end (the box end) of another section ofpipe.

The ends of the pipe, including the threads, are subject to damage whennot in actual use, such as from contact with other objects, or frombeing dropped, during transportation and storage. Such damage may renderthe pipe faulty or unusable, resulting in delay, hardship and increasedexpense. Devices known as “thread protectors” are commonly used toprotect the ends of the pipe, particularly the pipe threads thereon,from such damage. A “pin end” thread protector is connected to andprotects the pin end of the pipe and a “box end” thread protector isconnected to and protects the box end of the pipe. The thread protectorsare designed to prevent damage to the respective pipe ends when the pipeimpacts other objects, the ground or otherwise is subjected to externalimpact. Example prior art thread protectors are disclosed in U.S. Pat.Nos. 4,957,141; 5,195,562; and U.S. Pat. No. 5,244,015, all to Dreyfusset al., and U.S. Pat. No. 4,809,752 to Strodter, all of which are herebyincorporated herein by reference in their entireties.

An industry standard for thread protectors for premium pipe is the“Shell®” test. A Specification for the Shell test entitled “Shell OilSpecification for Thread Protectors March 1988” is attached hereto andhereby incorporated herein by reference in its entirety. The Shell testis also described in Technical Paper ADC/SPE 17209 entitled “PerformanceEvaluation of Commercially Available Thread Protectors,” authored by E.J. C. Spruijt and also hereby incorporated herein by reference in itsentirety (the first two pages of the Paper are attached hereto). TheShell test subjects the thread protector and pipe to an impact energy todetermine if the thread protector being tested can protect the pipe endsfrom damage. One type of Shell test simulates installing the threadprotector on the pipe, raising the pipe off the ground, and thendropping the pipe axially to evaluate the effectiveness of the threadprotector by determining whether the end of the steel pipe was damaged.The Shell test requires that the thread protector present the pipe endsfrom damage during different tests at varying temperatures. Since thepipe is used in various environments and thus exposed to a wide range oftemperatures, the test is performed at varying temperatures, such as150° F., 70° F. or ambient, and −50° F., to insure that the threadprotector will protect the pipe when exposed to heat or cold over time.For testing pipes having nominal outer diameters of between 4 inches and8 ¾ inches, for example, the thread protector and pipe may be subjectedto 1200ft/lbs of energy at temperatures of 150° F. and again at 70° F.(ambient). A third test subjects the thread protector and pipe to 600ft/lbs of energy at a temperature of −50° F. For example, a section ofpipe having a nominal outer diameter of between about 4.0 inches andabout 8 ¾ inches with a weight of 430.4 lbs is dropped 33.6 inchestransmitting 1205 ft/lb of impact energy onto the thread protector andpipe end. To determine the protective capacity of the protector, thepipe is inspected for damage. Damage may include dents, damaged threads,out-of-roundness, or other damage affecting the use of the pipe in thefield. Although it is preferred that the thread protector not bedamaged, damage to the thread protector is not a criteria in the Shelltest. The Shell test for larger diameter pipe requires a larger impact,such as 1500 ft/lbs at 150° F. and 70° F. or ambient, and 800 ft/lbs at−50° F.

The thread protector must prevent substantial impact energy fromreaching the pipe end to adequately protect the pipe from the impactenergy. Prior art thread protectors have been designed as strong aspossible to withstand the anticipated impact energy. Thus, prior artthread protectors are large, sturdy and rigid members which will preventdamage to the pipe and to the thread protector itself.

To provide this strength and rigidity, many prior art thread protectorsare constructed of a composite of steel and plastic. One of the mostcommercial thread protectors is manufactured by Drilltec Patents andTechnologies Company, Inc. and is known as Drilltec's ESPS™ protector.This protector includes an outer steel sleeve crimped over an innerplastic member. The steel sleeve has the effect of providing stiffnessand rigidity to the protector, enabling it to withstand impact energy.The Drilltec protector is disclosed in U.S. Pat. Nos. 4,957,141;5,195,562; and 5,244,015. Other prior art thread protectors, such asDrilltec's STP™, Drilltec's SSP™ and Molding Specialties, Inc.'s Magnummodel thread protectors are constructed of plastic and often includeadditives such as fibers or particles of another material, but without asteel sleeve. FIGS. 1A and 1B illustrate a pin end thread protector anda box end thread protector, respectively, similar to that manufacturedby Molding Specialties, Inc. for a pipe having a nominal outer diameterof 7 inches.

The prior art thread protectors are believed to have variousdisadvantages. Because these protectors are large and heavy, theyrequire a substantial quantity of material, typically both steel andplastic, for their construction. The more material that is required toproduce the protector, the greater the manufacturing cost. Prior artprotectors are thus expensive. Further, the larger, bulkier and heavierthe protector, the more difficult and time consuming the handling of theprotectors and the greater the need for special handling equipment,particularly for large diameter pipe thread protectors.

Additionally, various prior art thread protectors constructed without asteel sleeve are believed to warp and become out-of-round or deformed,thus making it difficult or impossible them to be installed onto thepipe end, thereby decreasing their usefulness. Further, typical priorart thread protectors constructed primarily of plastic are believed tobe generally ineffective at withstanding significant impact energy. Inparticular, typical prior art thread protectors constructed of allplastic material, or plastic containing particles of other material, arebelieved to generally not pass the Shell test without being beefed up insize so as to use a substantial amount of material, thus substantiallyraising the cost of manufacturing the protector.

Thus, there remains a need for a thread protector capable of protectingpipe ends that requires less material and is thus more cost effective tomanufacture (material and labor) than prior art thread protectors.Preferably, the thread protector does not include a steel sleeve and maybe made of a material lighter than steel. Ideally, the thread protectorcould be designed to plastically deform under impact so that the impactenergy is transformed into internal friction and thermal energy; thethread protector thus using up or substantially reducing the transmittedenergy and preventing the energy from reaching or damaging the threadsof the attached pipe. Especially well received would be a threadprotector that is made substantially of plastic and that passes theShell test. Further, the thread protector is preferably reduced in sizeand material than many prior art thread protectors, thereby reducingshipping and handling requirements.

The present invention overcomes one or more of these deficiencies in theprior art.

SUMMARY OF THE INVENTION

In accordance with the invention, there is provided a thread protectorfor protecting threads on the end of a pipe, the thread protector havinga base portion with a first end having a threaded portion extendingtherefrom and threadably engageable with the pipe and a second endhaving an elongated annular bumper extending axially therefrom. Theelongated bumper has an average length of at least about 1.1 inches andpreferably at least about 2 inches. The ratio of the length to theaverage width of the elongated bumper is at least about 1.2 andpreferably about 3 or more.

The base, threaded portion and elongated annular bumper may beconstructed primarily of non-metallic material, such as high densitypolyethylene material. The base, threaded portion and elongated annularbumper may be constructed of material that has a minimum izod impactyield, or break point of about 5.6 ft-lb/inch. The thread protector ispreferably capable of passing the Shell test.

The elongated bumper preferably has an inner taper forming a conicalinterior portion. The elongated bumper may include a plurality ofcut-outs each having an average width of between approximately 8{fraction (1/32)} inch and approximately ⅛ inches. The cut-outs may beslots that intersect the terminal end of the elongated bumper.

The elongated bumper may include at least two bumper arms. The elongatedbumper may include at least one base tear starter.

In an alternate embodiment, the bumper may have at least one taper alongits length forming an angle of at least about 1.8 degrees. In anotherembodiment, the ratio of the average length of the elongated bumper tothe maximum outer diameter of the thread protector is at least about0.20. In yet another embodiment, the ratio of the average length of thebumper to the nominal outer diameter of the pipe may be at least about0.22.

Other objects and advantages of the invention will be apparent from thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of preferred embodiments of the invention,reference will now be made to the accompanying drawings wherein:

FIG. 1A is a partial cross-sectional view of a prior art pin end threadprotector;

FIG. 1B is a partial cross-sectional view of a prior art box end threadprotector;

FIG. 2 is a partial cross-sectional view of one embodiment of a pin endthread protector made in accordance with the present invention;

FIG. 3 is a enlarged view of a portion of the thread protector FIG. 2showing the base and thread members of the protector;

FIG. 4 is a side view of an alternative embodiment of the terminal endof the bumper of the pin end thread protector shown in FIG. 2;

FIG. 5 is a side view of another alternative embodiment of the bumper ofthe pin end thread protector shown in FIG. 2 having open cut-outs madein accordance with the present invention;

FIG. 6 is a side view of still another alternative embodiment of thebumper of the pin end thread protector shown in FIG. 2 having enclosedcut-outs made in accordance with the present invention;

FIG. 7 is a partial cross-sectional view of another embodiment of thepin end thread protector of FIG. 2 with no cover;

FIG. 8 is a partial cross-sectional view of still another embodiment ofthe pin end thread protector of FIG. 2 with a disc-like cover;

FIG. 9 is a graph showing the percent strain of a test piece of Phillips66 Marlex HXM 50100 polyethylene material as stress (psi) is applied tothe material to its yield point;

FIG. 10 is an enlargement of the graph shown in FIG. 9 for percentagestrain in the range of 0 to 20% for the Phillips 66 Marlex HXM 50100polyethylene material as stress (psi) is applied to the material;

FIG. 11 is a partial cross-sectional view of one embodiment of a box endthread protector made in accordance with the present invention;

FIG. 12 is a perspective view of a pin end thread protector made inaccordance with the present invention showing the dissipation of impactenergy in the protector after impact;

FIG. 13 is a partial cross-sectional view of another embodiment of a pinend thread protector having multiple bumpers and base tear starters madein accordance with the present invention;

FIG. 14 is a perspective view of the thread protector of FIG. 13;

FIG. 15 is a partial cross-sectional view of another embodiment of a boxend thread protector having multiple bumpers and base tear starters madein accordance with the present invention;

FIG. 16 is a perspective view of the thread protector of FIG. 15;

FIG. 17 is a partial cross-sectional view of another embodiment of a pinend thread protector made in accordance with the present invention;

FIG. 18 is a partial cross-sectional view of another embodiment of a boxend thread protector made in accordance with the present invention;

FIG. 19 is a partial cross-sectional view of still another embodiment ofa pin end thread protector made in accordance with the presentinvention;

FIG. 20 is a partial cross-sectional view of still another embodiment ofa box end thread protector made in accordance with the presentinvention;

FIG. 21 is a partial cross-sectional view of yet still anotherembodiment of a box end thread protector made in accordance with thepresent invention;

FIG. 22 is a partial cross-sectional view of still yet anotherembodiment of a box end thread protector made in accordance with thepresent invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the invention are shown in the above-identifiedfigures and described in detail below. In describing the preferredembodiments, like or identical reference numerals are used to identifycommon or similar elements. The figures are not necessarily to scale andcertain features and certain views of the figures may be shownexaggerated in scale or in schematic form in the interest of clarity andconciseness.

Referring now to FIG. 2, there is shown one embodiment of a pin endthread protector 50 of the present invention capable of protecting malethreads 42 on the exterior 44 of a pin end 46 of pipe 48. Pipe 48 shownin FIG. 2 has a nominal outer diameter of 7 inches. The thread protector50 includes a base 56, a box 52 projecting axially from the base 56 inone direction and engageable with the pin end 46 of pipe 48, and abumper 62 projecting axially from the base 56 in the opposite direction.The box 52 extends from one side of the base 56 to one end 50 a of theprotector 50, while the bumper 62 extends from the other side of thebase 56 to the other end 50b of the protector 50.

The base 56 is an annular portion located generally at the mid-portionof protector 50 and proximate to the terminal end 49 of the pipe 48. Thebase 56 may, for example, have a generally rectangular cross-sectionwith a thickness 56 a and a height 56 b, and includes an internalannular surface, or seat, 57 for seating against the terminal end 49 ofthe pipe 48 when the protector 50 is installed on the pipe 48. The seat57 preferably has a radial width which is at least as great as theradial width of the terminal end 49 of pipe 48.

The bumper 62 of the present invention is an elongated sleeve-likeannular member extending from the base 56 and having a height, orlength, L and a thickness W. The length. L of the bumper 62 is measuredfrom the terminal end 64 of the bumper 62 to the other end 63 of thebumper 62 adjacent the base 56. It should be appreciated that the otherend 63 of the bumper 62 is not distinct and is loosely defined as thepoint where the bumper 62 first begins a taper A 2 as hereinafterdefined. As shown in FIG. 4, the terminal end 64 of the bumper 62 neednot be even, forming varying lengths L 1 , L 2 . . . Ln around theterminal end 64. In such an embodiment, the reference “L” refers to theaverage length of the varying lengths L 1 , L 2 . . . Ln. If the bumper62 has differing thicknesses W 1 , W 2 . . . Wn, or is tapered, as shownfor example in FIG. 2, the reference “W” refers to an average thicknessor width of bumper 62.

The elongated bumper 62 may have an inner taper along its length Lforming a conical portion and thus have a cross-sectional area that isless than 100% of the rectangular cross-sectional area of the length Ltimes the greatest thickness W of the bumper 62. For example, the bumper62 may have a total taper along its length L forming an angle of greaterthan about 1.8 degrees. The exemplary bumper 62 of FIG. 2 possesses across-sectional area that is less than about 80% of the totalrectangular cross sectional area between ends 63, 64; an outer taper A 1extending from about the mid-point 62 c of the length L to the terminalend 64 of the bumper 62 of between about 4.0-5.0 degrees; a first innertape A 2 extending from the end 63 of the bumper 62, or from the base56, to about the mid-point 62 c of the length L of between about 6.0-6.5degrees; and a second inner taper A 3 of between about 8.0-8.5 degreesextending from about the mid-point 62 c to the terminal end 64 of thebumper 62. Alternately, the bumper 62 may be viewed as having anon-uniform cross-section. In the embodiment of FIG. 2, for example, thebumper 62 has thicknesses ranging from a thickness W 3 of about 0.55inches, to a thickness W 2 of about 0.46 inches to a thickness W 1 ofabout 0.20 inches. The average thickness W of the bumper 62 is about0.41 inches. It should be understood, however, that the thread protector50 of the present invention is not limited to tapered elongated bumpers62 or to any of the above specific examples.

The thread protector 50 is preferably constructed of a material thatplastically deforms under impact so that the impact energy istransformed into internal friction and thermal energy; the threadprotector 50 thus using up or substantially reducing the transmittedenergy and preventing the energy from reaching or damaging the threadsof the attached pipe 48. The thread protector 50 is thus preferablyconstructed of a material that will absorb substantial energy whensubjected to external forces, such as the impact energy during the Shelltest. The material absorbs the impact energy by deflecting, deforming orflexing and/or yielding or failing, each of these requiring energy. Inthe preferred embodiment of FIG. 2, the thread protector 50 isconstructed primarily of a material that has a substantial izod impactstrength, as defined in the ASTM guidelines Designation D 256-93aentitled Standard Test Methods for Determining the Pendulum ImpactResistance of Notched Specimens of Plastics, attached hereto and herebyincorporated herein by reference, and a substantial compressivestrength, as defined in the ASTM guidelines Designation D 695-96entitled Standard Test Method for Compressive Properties of RigidPlastics, attached hereto and hereby incorporated herein by reference.Materials with these characteristics provide good energy absorption. Seee.g. pages 11 and 12 of the Marlex Phillips 66 Brochure entitled“Engineering Properties of Marlex Resins”, hereby incorporated herein byreference in its entirety. Other relevant reference materials includethe Marlex Phillips 66 Brochures entitled “Polyethylene TIB 1 Properties& Processing” and “Blow Molding Resins: Information on MarlexPolyethylene Resins.”

The thread protector 50 is preferably constructed primarily of a highdensity polyethylene material, such as Phillips 66 Marlex® HHM 5502 BNor HXM 50100. The nominal physical properties and mechanical propertiesof these materials are set forth on an attachment entitled “NominalPhysical Properties”, hereby incorporated herein by reference. The IzodInpact yield, or break point of HHM 5501 is 5.6 ft-lb./inch at roomtemperature. Typical values for the tensile strength and elongation ofvarious materials are also attached hereto and are hereby incorporatedherein by reference. Additional information about HXM 50100 in theMarlex Brochure entitled “Polyethylene Data Sheet Marlex HXM 50100” isalso attached hereto and hereby incorporated herein by reference.

Referring now to FIGS. 9 and 10, there are shown stress-strain graphswith curves 80 a, 80 b for the material HXM 50100. The curves 80 a, 80 bshow properties for yield strength and ultimate strength of thismaterial for use in the construction of a thread protector 50 made inaccordance with the present invention. The curves 80 a, 80 b illustratea tensile yield of 4100 psi, a tensile break of 2800 psi and anelongation at yield 9.7% and break 861 psi. The area 82 a, 82 b underthe curves 80 a, 80 b represents the impact energy loss, or absorbed, toproduce a given amount of deformation in the material.(Area=Force×Distance (or Work)) The graphs illustrate that the HMX 50100material does not completely fail, but will deform and use up the energyfrom an external impact. Thus, external impact energy expended in athread protector 50 constructed of this material in accordance with thepresent invention tends to absorb sufficient energy from the impact todissipate a sufficient amount of that energy to avoid damage to the endof the attached pipe. Such characteristics tend to be maintained in thematerial throughout the range of temperatures and impact energy of theShell test. It should be appreciated that the energy absorption,deflection and failure characteristics of various materials, such asplastics, are difficult to measure with precision and may vary amongeven samples of the same type of material.

In other embodiments, the thread protector 50 may be constructed of lowdensity polyethylene. Low density polyethylene generally possessesdesirable deformation characteristics in accordance with the presentinvention through low temperature ranges, such as −50° F. For yetanother example, the protector 50 may be constructed of a plastic, suchas high density polyethylene, with one or more additives such as a metal(e.g. aluminum), or metal and other material, dispersed in the plastic.

Referring again to FIG. 2, the dimensions of bumper 62 may vary with thesize of the pipe 48 to be protected. The larger the pipe 48, the greaterthe protection required because of its increased weight. The followingpreferred dimensions have been found for pipe 48 having a nominal outerdiameter 48 a of 7.0 inches. The length L of the elongated bumper 62made in accordance with the present invention is preferably at leastabout 1.1 inches and more preferably is at least about 2.0 inches.Further, the length L and thickness W of the elongated bumper 62preferably have a ratio of the length L to thickness W (L/W) of at leastabout 1.2 and preferably at least 3 or more. In the embodiment of FIG.2, for example, the length L is about 2.0 inches and the (average)thickness W is about 0.41 inches; the ratio L/W being about 4.88. Thus,the L and W may be varied so as to maintain the preferred L/W ratio.Additionally, the length L of the bumper 62 plus the height 56 b of thebase 56 is preferably at least 1.75 inches. In the embodiment of FIG. 2,for example, the height 56 b is about 0.38 inches; L+56 b thus beingabout 2.38 inches. The length L may also be based on its ratio with theouter diameter Od of the thread protector 50. The ratio of length L tothe outer diameter Od of the thread protector 50 (L/Od) may, inaccordance with the present invention, be greater than about 0.15. Forexample, the outer diameter Od of the protector 50 of FIG. 2 is about7.5 inches. The ratio L/Od is thus about 0.27. Another method formeasuring the length L of elongated bumper 62 may be the ratio of thelength L to the nominal outer diameter 48 a of the pipe 48 to beprotected; the ratio L/48 a in accordance with the present inventionbeing at least about 0.15. For example, the protector 50 of FIG. 2,being designed for a pipe 48 having an nominal outer diameter of about7.0 inches, has a ratio L/48 a of about 0.29.

The material for the protector 50 may also vary with the size of thepipe 48 to be protected and the ultimate location for shipment of thepipe. The dimensions of the bumper 62 will also be influenced by theproperties of the material selected for the protector 50, such as theimpact resistance, energy absorption, compressive strength, stiffness,temperature durability, tensile yield or other pertinent capabilities ofthe material of which the protector 50 is made. The preferred materialfor protector 50 is Phillips 66 Marlex HHM 5502 BN. For example, aprotector 50 made of the preferred material and having a bumper 62 witha length of at least about 1.1 will pass the 1200 ft/lb Shell® test.

It should be understood that the material for protector 50 and thedimensions of bumper 62 need not meet more than one of the abovecriteria in accordance with the present invention; and, in each case, isnot limited to the specific examples of the preferred embodimentsprovided.

Further, it should be understood that the present invention is notlimited to thread protectors 50 that pass the Shell test.

Referring now to FIGS. 2 and 3, the box 52, having ends 52 a and 52 b,is capable of threadingly engaging the pipe threads 42 of pin end 46.For example, the box 52 is shown having an internal bore 54 with aplurality of thread members 55 formed at least partially thereon. Thethread members 55 are formed to be threadingly engageable with the pipethreads 42 and each have an approximate height H 1 and thickness T 1(FIG. 3). The height H 1 of thread member 55 is the distance from thecrest to the root of the thread member 55 and the thickness T 1 is thedistance between the centers of adjacent roots on each side of a threadmember 55. The bore 54 and thread members 55 may be formed in anysuitable shape and configuration to be threadingly matable with the pipethreads 42 on pipe 48. For example, the height H 1 and thickness T 1 ofthread members 55 may be dimensioned to fit a certain type of pipethreads 42. It should be appreciated that pipe threads 42 may have oneor more steps and may be straight or tapered.

The box 52 may also include an annular recess 58 formed in the bore 54of the box 52 adjacent to the thread member 55 a that is closest to thebase 56. In addition, a second annular recess 58 c may be formed in thebore 54 adjacent to the thread member 55 b that is closest to the end 52a of box 52. The recesses 58 and 58 c may be formed with any desireddimensions suitable for use with the present invention. In theembodiment of FIGS. 2 and 3, the recess 58 has a depth 58 a ofapproximately equal to or slightly greater than the height H 1 of threadmember 55. As an example, the thread members 55 in thread protector 50of FIG. 2 (for use with a pipe 48 having an nominal outer diameter 48 aof about 7.0 inches) may be formed with a thickness T 1 of about 0.200inches and a height H 1 of about 0.063, and the recess 58 formed with adepth 58 a of approximately 0.200 inches. The width 58 b of recess 58may also be specifically dimensioned, such as 0.063 inches.

The inclusion of recess 58 in the box 52 of protector 50 allowsformation of the thread members 55 in the box 52 such as by allowing athreading tool, an example being a tap device (not shown), to be movedin and out of the bore 54. Without the recess 58, as the threading toolcompletes the threading of the bore 54, a hair, string or shaving ofmaterial may be formed and remain in the box 52 after the threading toolis removed. Once the pipe 48 is threadingly engaged with the base 54,the shaving may become embedded in the pipe threads 42 and may preventthe pipe 48 from later being threaded into another device, such as apipe joint (not shown), or may remain attached to the bore 54 and bevery difficult to remove therefrom. The recess 58 may also serve as agrease pocket for retaining grease carried on the pipe threads 42.

Referring now to FIG. 12, in operation, upon impact to the elongatedbumper 62 and pipe end (not shown), the energy E from the impact spreadsthrough the material of the bumper 62, such as in a fan-like patternbeginning at the terminal end 64. As the energy E propagates through thematerial of bumper 62 towards bumper end 63, the energy is absorbed andthus dissipates as the bumper 62 flexes, deforms and deflects. Becauseeach of these processes requires energy, the amount of energy which canreach the pipe end (not shown) and cause damage is lessened. The energyof a relatively small external impact force to the terminal end 64 maybe absorbed or dissipated in only a portion of the elongated bumper 62.A larger impact to the terminal end 64 or to another location on theelongated bumper 62 increases the flexing, deforming, and deflectingdown the length L of the elongated bumper 62, which increases theabsorption of energy. If the impact energy is great, it may besufficient to crack, tear or fracture the bumper 62, and possibly eventhe base 56 or box 52. This failure of the material significantlyenhances the absorption of energy such that when the impact energyreaches the pipe 48 (FIG. 2) it is insufficient to damage the pipe 48.

In another aspect of the present invention, it may be desirable toconfigure the thread protector 50 to avoid premature cracking, yieldingor failure. The protector 50 may, for example, be susceptible toyielding and failure (and thus premature failure) at locations on theprotector 50 having a stress concentration, or radical change instiffness, such as at abrupt changes in the geometry of the protector50. Depending on various factors, such as, for example, the shape andconfiguration of the protector 50, the type of material used toconstruct the protector 50 and the size of the pipe 48 engaged by theprotector 50, it may be desirable to make gradual transitions instiffness across the thread protector 50, and to remove or reduce stressconcentrations in the protector 50. For example, the thread protector 50may be generally formed with slopes or tapers at various locations whereabrupt geometric changes in the protector 50 occur. For another example,where stress concentrations may exist, such as at corners formed in thethread protector 50, additional corners may be formed proximate to theexisting corners to reduce the stress concentration at each corner.

The embodiment of FIG. 2 has specific features that assist in avoidingpremature failure. The recess 58 may be a stress concentration locationand thus a location on the protector 50 susceptible to failure. Toassist in reducing that susceptibility, a groove 66 may be formed in theprotector 50 proximate to the recess 58, such as an annular groove 67formed into the cover 81. Further, the depth 66 a (FIG. 3) of the groove66 may, if desired, be minimized, effectively increasing the thicknessof the base 56 and generally strengthening the protector 50 in thatarea.

Additionally, an annular shoulder 68 may be formed between the groove 66and recess 58, as shown, for example, in FIG. 2. Increasing the height68 a of the shoulder 68 will generally increase the strength of theprotector 50 at base 56 and assist in preventing premature fracturing ofthe protector 50. The shoulder 68 may function as the seat 57 forseating against the terminal end 49 of the pipe 48. Further, theprotector 50 may be configured such that the shoulder 68 forms asubstantial seal with the terminal end 49 of the pipe 48, preventingmoisture from entering the pipe end 46 when the pipe 48 is engaged witha protector 50 having a cover 81. In such instance, the width 68 b ofthe shoulder 68 (FIG. 3) may be formed to correspond with the thicknessof the pipe end 49. In other configurations, the protector 50 may beformed so that the shoulder 68 does not seat against the terminal end 49of the pipe 48 or form a seal therewith. The further the shoulder 68 isfrom the pipe 48, the better the energy absorption by the protector 50.

For another example of a feature that assists in avoiding prematurefailure, the area of intersection 70 (FIG. 2) of the elongated bumper 62and the base 56 may be a location of significant change in stiffness. Inthe embodiment of FIG. 2, the end 63 of the elongated bumper 62 isconnected to the base 56 at the area of intersection 70. To assist inreducing the dramatic change in stiffness, the base 56 may be formedwith a relatively significant width 56 a and thickness 56 b. Further,the end 63 of the bumper 62 may be tapered, having an increased width W3 proximate to the intersection 70, assisting in reducing stressconcentrations and decreasing the extreme stiffness of the protector 50in that area.

Referring again to FIG. 2, the thread protector 50 may be constructedwith any desirable overall dimensions and material, such as tocorrespond with different sizes of pipes 48. For example, differentsizes of thread protectors 50 may be made to fit pipes 48 having nominalouter diameters 48 a ranging from 2 ⅜ inches to 20 inches. Further, thethread protector 50 may be constructed to have a minimal weight. Forexample, a thread protector 50 capable of passing the Shell test andprotecting threads 42 on the end 46 of a premium grade pipe 48 having annominal outer diameter 48 a of about 7.0 inches may be formed having aweight of about 2.43 pounds.

The thread protector 50 may be formed by any suitable manufacturingprocess, such as by injection molding. The thread protector 50 may, forexample, be made as a single integral molding. It should be taken intoaccount that the type of manufacturing process used may affect theenergy absorption, deflection and failure characteristics of the threadprotector 50.

Now referring to FIGS. 5 and 6, the elongated bumper 62 may include aplurality of cut-outs 72 to increase energy absorption of the protector50. The cut-outs 72 provide a stress concentration to encourage thematerial of the protector 50 proximate to the cut-outs 72 to tear uponimpact, thereby redistributing the impact energy over a large volume ofprotector material and also using up impact energy, further minimizingthe transmission of impact energy to the attached pipe (not shown). Thecut-outs 72 may be formed in any suitable shape, quantity and locationin the wall of the bumper 62. In FIG. 5, for example, each cut-out 72preferably forms a slot 76 that intersects the terminal end 64 of theelongated bumper 62 at its end 74. The slots 76 are thus open at theirends 74. Each slot 76 extends through the thickness of the bumper 62 andhas a narrow width (not shown). Each cut-out 72 of the embodiment ofFIG. 5, for example, has an average width of between approximately{fraction (1/32)} inch and approximately ⅛ inch.

The corners C at the ends 73, 74 of the cut-outs 72 may be left sharpand not rounded to enhance the cracking and tearing of the material. Inthe embodiment of FIG. 5, the cut-outs 72 extend partially across thelength L of the elongated bumper 62 and terminate at angles 78 at theirends 73.

In FIG. 6, the cut-outs 72 are internal cracks, or slots, 76 a havingends 73 a, 74 a both disposed in the elongated bumper 62. The internalslots 76 a are thus closed and have corners C formed at ends 73 a, 74 a.The internal slots 76 a are shown also extending through the thicknessof the bumper 62, having narrow widths (not shown) and having corners Cthat are sharp and not rounded.

Referring to FIG. 8, in another aspect of the invention, the bumper 62may include two or more installation slots 62 d, which may be used witha tool for threading and unthreading the protector 50 from the pipe 48,as is well known in the art. The embodiment of FIG. 8, for example,includes four installation slots 62 d that are about 0.75 inches wideand about 0.50 inches deep, which are engageable with the tool, such asa standard installation bar, for rotating the protector 50 on and offthe pipe 48.

Referring now to FIGS. 2, 7 and 8, the central opening 51 of theprotector 50 may be entirely or partially covered or uncovered. Forexample, the protector 50 may be completely open, such as shown in FIG.7. In other embodiments, as shown for example in FIG. 8, the protector50 may include a central cover 81 extending from the base 56. Thecentral cover 81 may be formed to partially or completely cover theopening 51, such as the disc-like cover 81 a of FIG. 8. For example,when the central cover 81 completely covers the opening 51, debriscannot enter the pipe end 46 from outside the protector 50. In yet otherconfigurations, as shown, for example in FIG. 2, the central cover 81may be a recessed member 82. The recessed member 82 may be formed withany desirable shape or configuration. In FIG. 2, the recessed member 82is a cup-like member 84 extending from the base 56 that allows thethread protector 50 and pipe 48 to be lifted. A device, such as a hook(not shown), may be inserted into the cup-like member 84 when the pipe48 and connected thread protector 50 are in a non-vertical position tolift and/or lower the protector 50 and pipe 48.

Referring now to FIG. 11, an embodiment of a box end thread protector100 capable of protecting female threads 42 on the interior 45 of a boxend 47 of pipe 48 made in accordance with the present invention isshown. The above description of the pin end thread protector 50 and itsuse generally applies equally to the protector 100, except as otherwisedescribed herein. The thread protector 100 includes a base 156, a pin152 projecting axially from the base 156 in one direction and engageablewith the box end 47 of the pipe 48, and an elongated bumper 162projecting axially from the base 156 in the opposite direction. The pin152 thus extends to the one end 100 a of the protector 100, while thebumper 162 extends to the other end 100 b of the protector 100.

The base 156 is a portion of the protector 100 located proximate to theterminal end 49 of the pipe 48. The base 156 may include an annularsurface, or seat, 57 that faces and may abut the terminal end 49 of thepipe 48 when the pipe 48 is engaged with the protector 100. The seat 57preferably has a radial width which is at least as large as the radialwidth of the terminal end 49 of the pipe 48. This allows seat 57 toprotect the terminal end 49 from damage. The base 156 may be formed witha generally rectangular, or square, cross section, having a height 156 bextending from the seat 57 to the end 163 of the bumper 162 proximate tothe beginning of the taper, and a thickness 156 a, such as shown in FIG.11. In other embodiments (not shown), the base 156 may be merely thecross-section of the protector 100 adjacent the location of the seat 57,in which instances the elongated bumper 162 extends substantiallydirectly from the seat 57.

The length L of the bumper 162 of protector 100FIG. 11 is measured fromthe terminal end 164 of the bumper 162 to the opposite end 163 of thebumper 162, or to the base 156. Again it should be appreciated that theother end 163 of the bumper 162 is not distinct and is loosely definedas the point where the bumper 162 first begins a taper A 5 ashereinafter defined. If the bumper 162 has differing thicknesses W 1 , W2 . . . Wn, or is tapered, as shown for example in FIG. 11, thereference “W” refers to the average thickness of bumper 162.

The length L of the elongated bumper 162 made in accordance with thepresent invention may be at least about 1.5 inches. Further, the lengthL of the bumper 162 plus the height 156 b of the base 156 may be atleast 1.8. In the preferred embodiment of FIG. 11, for example, thelength L of bumper 162 is at least about 1.8 inches and the length L ofthe bumper 162 plus the height 156 b of the base 156 is at least about1.9 inches and preferably over 2.2.

The dimensions of the elongated bumper 162 may vary with the size of thepipe 48 to be protected. The following preferred dimensions have beenfound for pipe 48 having a nominal outer diameter of 7.0 inches. Thelength L and thickness W of the elongated bumper 162 made in accordancewith the present invention may be formed such that the ratio of thelength L to thickness W (L/W) is at least about 2.0 and preferably over3. In the embodiment of FIG. 11, for example, the length L is about 1.8inches and the average thickness W is about 0.45 inches; the ratio L/Wthus being about 4.0. The length L may also be measured based on itsratio with another variable, such as for example the outer diameter Odof the thread protector 100. The ratio of length L to the outer diameterOd of the thread protector 100 (L/Od) may, in accordance with thepresent invention, be greater than about 0.20. For example, the outerdiameter Od of the protector 100 of FIG. 11 is about 7.7 inches. Theratio L/Od is thus about 0.23. Another method for measuring the length Lof elongated bumper 162 may be the ratio of the length L to the nominalouter diameter 48 a of the pipe 48 to be protected; the ratio L/48 a inaccordance with the present invention being at least about 0.22. Forexample, the protector 100 of FIG. 11 is matable with a pipe 48 havingan nominal outer diameter 48 a of about 7.0 inches; the ratio L/48 athus being about 0.26.

It should be understood that the bumper 162 need not meet more than oneof the above criteria in accordance with the present invention; and, ineach case, is not limited to the specific examples provided.

Still referring to FIG. 11, the elongated bumper 162 may be at leastpartially tapered along its length L and have a cross-sectional areathat is less than 100% of the rectangular cross-sectional area of thelength L times the greatest thickness W of the bumper 162. For example,the bumper 162 may have a total taper along its length L forming anangle of at least about 1.8 degrees. The exemplary bumper 162 of FIG.11, for example, possesses a cross-sectional area that is about 70% ofthe total rectangular cross-sectional area between ends 163, 164; anouter taper A 4 extending from about the mid-point 162 c of the length Lto the terminal end 164 of the bumper 162 of between about 4.0-5.0degrees, and an inner tape A 5 of between about 12.0-13.0 degreesextending from the terminal end 164 to the end 163 of the bumper 162. Inanother embodiment, the bumper 162 may be formed with tapers similar totapers A 1 , A 2 and A 3 of bumper 62 described above with respect toprotector 50 of FIG. 2. Alternately, the bumper 162 may be viewed ashaving a non-uniform cross-section. In the embodiment of FIG. 11, forexample, the bumper 162 has thicknesses ranging from a thickness W 3 ofabout 0.68 inches to a thickness W 1 of about 0.20 inches. The averagethickness W of the bumper 162 is about 0.45 inches. It should beunderstood, however, that the thread protector 100 of the presentinvention is not limited to tapered elongated bumpers 162 or to any ofthe above specific examples.

The pin 152, having ends 152 a, 152 b, respectively, is capable of atleast partially engaging the box end 47 and pipe threads 42 of pipe 48.For example, the pin 152 of the embodiment of FIG. 11 is shown having anouter surface 154 with a plurality of thread members 155 formed at leastpartially thereon. The thread members 155 are formed to be matable withthe pipe threads 42 and may be shaped and sized similarly as describedabove with respect to thread members 55 of protector 50.

Still referring to FIG. 11, the thread protector 100 may be constructedin any desirable overall size, such as to correspond with differentsizes of pipes 48. For example, different sized thread protectors 100may be made to fit pipes 48 having nominal outer diameters 48 a ofranging from 2 ⅜ inches to 20 inches. Further, the thread protector 100may be constructed to have a minimal weight. For example, the threadprotector 100 for passing the Shell test and protecting premium qualitypipe having an nominal outer diameter 48 a of about 7.0 inches may beformed having a weight about 1.75 pounds.

The option of including a groove 66 and shoulder 68 as described abovewith respect to protector 50 (FIG. 2) is not applicable to threadprotector 100. Further, referring still to FIG. 11, the central opening51 of the protector 100 may be entirely or partially covered oruncovered, similarly as described above with respect to protector 50. Inthe embodiment of FIG. 11, the central cover 81 extends from the end 152a of pin 152.

FIGS. 17-22 illustrate exemplary embodiments of the present inventionfor pipes of different diameters. FIG. 17 illustrates a pin threadprotector 400 for the pin end 46 of a pipe 48 having a nominal diameter48 a of 5.5 inches. The bumper length L is approximately 2.0 inches andthe average bumper width W is approximately 0.48 inches providing a W/Lratio of 4.19. The outside diameter Od is approximately 6.20 inchesproviding a L/Od of approximately 0.32 and a L/48 a of approximately0.36. The base length 56 b is approximately 0.20 inches providing animpact travel distance D of 2.19 inches between terminal bumper end 64and shoulder 57 adjacent the terminal end 49 of the pipe 48. End width W1 is approximately 0.23 inches and the base width W 3 is approximately0.63 inches. The cross-sectional area of bumper 62 with the innerconical portion 402 is approximately 75% of a rectangular area of basewidth W 3 times bumper length L.

FIG. 18 illustrates a box thread protector 410 for the box end 47 of apipe 48 having a nominal diameter 48 a of 5.5 inches. The bumper lengthL is approximately 1.20 inches and the average bumper width W isapproximately 0.38 inches providing a W/L ratio of 3.19. The outsidediameter Od is approximately 6.27 inches providing a L/Od ofapproximately 0.19 and a L/48 a of approximately 0.22. The base length156 b is approximately 1.08 inches providing an impact travel distance Dof 2.28 inches between terminal bumper end 164 and shoulder 157 adjacentthe terminal end 49 of the pipe 48. Shoulder 157 is formed in part by anannular retention flange 159 extending outwardly from base 156 to ensurethat the terminal end 49 of the pipe 48 is covered by shoulder 157 andtherefore protected. It should be appreciated that the outer diameter Odof pipe 48 will vary due to differences in thread types and pipedimensions. End width W 1 is approximately 0.25 inches and the basewidth W 3 is approximately 0.50 inches. The cross-sectional area ofbumper 62 with the inner conical portion 402 is approximately 75% of arectangular area of base width W 3 times bumper length L.

FIG. 19 illustrates a pin thread protector 420 for the pin end 46 of apipe 48 having a nominal diameter 48 a of 7 ⅝ inches. The bumper lengthL is approximately 2.06 inches and the average bumper width W isapproximately 0.52 inches providing a W/L ratio of 3.94. The outsidediameter is approximately 8.14 inches providing a L/Od of approximately0.25 and a L/48 a of approximately 0.27. The base length 56 b isapproximately 0.43 inches providing an impact travel distance D of 2.50inches between terminal bumper end 64 and shoulder 157 adjacent theterminal end 49 of the pipe 48. End width W 1 is approximately 0.37inches and the base width W 3 is approximately 0.68 inches. Thecross-sectional area of bumper 62 with the inner conical portion 402 isapproximately 71% of a rectangular area of base width W 3 times bumperlength L.

FIG. 20 illustrates a box thread protector 430 for the box end 47 of apipe 48 having a nominal diameter 48 a of 7 ⅝ inches. The bumper lengthL is approximately 1.94 inches and the average bumper width W isapproximately 0.51 inches providing a W/L ratio of 3.80. The outsidediameter Od is approximately 7.66 inches providing a L/Od ofapproximately 0.25 and a L/48 a of approximately 0.25. The base length156 b is approximately 0.29 inches providing an impact travel distance Dof 2.23 inches between terminal bumper end 164 and shoulder 157 adjacentthe terminal end 49 of the pipe 48. End width W 1 is approximately 0.30inches and the base width W 3 is approximately 0.72 inches. Thecross-sectional area of bumper 62 with the inner conical portion 402 isapproximately 71% of a rectangular area of base width W 3 times bumperlength L.

FIG. 17 is also illustrative of a pin thread protector for the pin end46 of a pipe 48 having a nominal diameter 48 a of 9 ⅝ inches. The bumperlength L is approximately 2.09 inches and the average bumper width W isapproximately 0.59 inches providing a W/L ratio of 3.56. The outsidediameter Od is approximately 10.71 inches providing a L/Od ofapproximately 0.20 and a L/48 a of approximately 0.22. The base length56 b is approximately 0.46 inches providing an impact travel distance of2.55 inches between terminal bumper end 64 and shoulder 157 adjacent theterminal end 49 of the pipe 48. End width W 1 is approximately 0.43inches and the base width W 3 is approximately 0.74 inches. Thecross-sectional area of bumper 62 with the inner conical portion 402 isapproximately 66% of a rectangular area of base width W 3 times bumperlength L.

FIG. 21 illustrates a box thread protector 440 for the box end 47 of apipe 48 having a nominal diameter 48 a of 9 ⅝ inches. The bumper lengthL is approximately 2.06 inches and the average bumper width W isapproximately 0.52 inches providing a W/L ratio of 3.96. The outsidediameter Od is approximately 9.86 inches providing a L/Od ofapproximately 0.21 and a L/48 a of approximately 0.21. The base length156 b is approximately 0.20 inches providing an impact travel distance Dof 2.26 inches between terminal bumper end 164 and shoulder 157 adjacentthe terminal end 49 of the pipe 48. End width W 1 is approximately 0.25inches and the base width W 3 is approximately 0.79 inches. Thecross-sectional area of bumper 62 with the inner conical portion 402 isapproximately 66% of a rectangular area of base width W 3 times bumperlength L.

FIG. 17 also illustrates a pin thread protector for the pin end 46 of apipe 48 having a nominal diameter 48 a of 13 ⅜ inches. The bumper lengthL is approximately 2.03 inches and the average bumper width W isapproximately 0.55 inches providing a W/L ratio of 3.71. The outsidediameter Od is approximately 14.02 inches providing a L/Od ofapproximately 0.14 and a L/48 a of approximately 0.15. The base length56 b is approximately 0.41 inches providing an impact travel distance of2.44 inches between terminal bumper end 64 and shoulder 157 adjacent theterminal end 49 of the pipe 48. End width W 1 is approximately 0.40inches and the base width W 3 is approximately 0.70 inches. Thecross-sectional area of bumper 62 with the inner conical portion 402 isapproximately 70% of a rectangular area of base width W 3 times bumperlength L.

FIG. 22 illustrates a box thread protector 450 for the box end 47 of apipe 48 having a nominal diameter 48 a of 13 ⅜ inches. The bumper lengthL is approximately 1.79 inches and the average bumper width W isapproximately 0.44 inches providing a W/L ratio of 4.03. The outsidediameter Od is approximately 13.91 inches providing a L/Od ofapproximately 0.13 and a L/48 a of approximately 0.13. The base length156 b is approximately 0.47 inches providing an impact travel distanceof 2.26 inches between terminal bumper end 164 and shoulder 157 adjacentthe terminal end 49 of the pipe 48. End width W 1 is approximately 0.25inches and the base width W 3 is approximately 0.64 inches. Thecross-sectional area of bumper 62 with the inner conical portion 402 isapproximately 70% of a rectangular area of base width W 3 times bumperlength L.

FIGS. 13-16 illustrate other exemplary embodiments of the presentinvention. The pin end thread protector 250 of FIGS. 13 and 14 is usefulfor protecting male threads 42 on the exterior 44 of a pin end 46 ofpipe 48, while the box end thread protector 300 of FIGS. 15 and 16 isuseful for protecting female threads 42 on the interior 45 of a box end47 of pipe 48. The protectors 250, 300 of the embodiment of FIGS. 13-16are generally similar to the exemplary embodiments of protectors 50 and100 described above with respect to FIGS. 2-12, except as otherwisedescribed herein.

Referring to FIG. 13, the base 256 is a portion of the protector 250located proximate to the terminal end 49 of the pipe 48. The base 256may be formed with a generally rectangular, or square, cross section. Inthe embodiment of FIG. 13, for example, the base 256 has a thickness 256a and a height 256 b. The base 256 may include a seat 257 that abuts theterminal end 49 of the pipe 48 when the pipe 48 is engaged with theprotector 250. In the embodiment of FIGS. 13 and 14, a cover 281 isshown extending from the base 256. The box 252 is capable of threadinglyengaging the pipe threads 42 of pin end 46. For example, the box 252 isshown having an internal bore 254 with a plurality of thread members 255formed at least partially thereon.

The outer surface 253 of the base 256 of protector 250 may be formedwith one or more base tear starters 259. The base tear starters 259 maybe formed in any suitable shape, quantity and location on the base 256.For example, the base tear starters 259 in the embodiment of FIG. 13include a pair of annular channels 260 a, 260 b formed into the outersurface 253 around the circumference of the base 256 and extendingpartially into the thickness 256 a of the base 256. However, theprotector 250 may instead be formed with one, or more than two, basetear starters 259 or channels 260 a, 260 b.

The elongated bumper 262 of protector 250 may include two or moreaxially extending bumper arms 286. In the embodiment of FIG. 13, twobumper arms 286 are included, the bumper arms 286 being annular outerand inner elongated ring shaped portions 288 a, 288 b. Further, the twoor more bumper arms 286 may be formed with different lengths L. Forexample, the radially outermost ring shaped portion 288 a of theembodiment of FIG. 13 has a length L 1 , and the ring shaped portion 288b has a length L 2 that is smaller length L 1.

Upon impact to the bumper 262, the impact energy may be transmittedbetween the two or more bumper arms 286. In FIGS. 13 and 14, forexample, the outer annular elongated ring shaped portion 288 a may flex,bend or deform upon external impact thereto. The impact energy maytravel around the outer ring shaped portion 288 a and transfer to theinner ring shaped portion 288 b, causing it to flex, bend or deform.Before reaching the base 256 or box 252, the energy may be substantiallydissipated or absorbed.

If impact energy reaches the base 256, base tear starters 259 providestress concentrations to encourage the material of the protector 250proximate to the starters 259 to flex or tear, thereby redistributingthe impact energy over a large volume of base 256 material and alsousing up impact energy, further minimizing the transmission of impactenergy to the attached pipe (not shown). With the embodiment shown inFIGS. 13-14, for example, the protector 250 may crack or fail at theannular channels 260 a, 260 b, instead of allowing energy to betransmitted to the pipe 48.

The above description of the pin end thread protector 250 made withreference to FIGS. 13 and 14 and its use applies generally equally tothe box end protector 300, such as shown in FIGS. 15 and 16, except asotherwise described herein. The thread protector 300 (FIG. 15) includesa base 356, a pin 352 projecting axially from the base 356 in onedirection and engageable with the box end 47 of the pipe 48, and anelongated bumper 362 projecting axially from the base 356 in theopposite direction. The pin 352 thus extends to one end 300 a of theprotector 300, while the bumper 362 extends to the other end 300 b.

Still referring to FIG. 15, the base 356 is a portion of the protector300 located proximate to the terminal end 49 of the pipe 48. The base356 may be formed with a generally rectangular, or square, crosssection. In the embodiment of FIG. 15, for example, the base 356 has athickness 356 a and a height 356 b. The base 356 may include a seat 357that abuts the terminal end 49 of the pipe 48 when the pipe 48 isengaged with the protector 300. In the embodiment of FIGS. 15 and 16, acover 381 is shown extending from the base 356.

The base of annular channel 260 b and the seat 357 form an annularretention flange 359 having a depth and a height in proportion to thethickness of the pin 352 and its terminal end 49. The retention flange359 remains in place, in tact, and against the terminal end 49 of pin352 upon impact by another object against the end of thread protector300. The protector 300 is easily removed from the pipe 352 since nomajor stresses pass through the retention flange 359. With the retentionflange 300 in place, there is no damage to the terminal end 49 of thepipe 352. Also the retention flange 359 prevents the ingress of foreignmatter and therefore prevents environmental damage.

The pin 352, having ends 352 a, 352 b, is capable of at least partiallyengaging the box end 47 and pipe threads 42 of pipe 48. For example, thepin 352 of the embodiment of FIG. 15 is shown having a plurality ofthread members 355 formed at least partially thereon. The thread members355 may be formed similarly as described above with respect to protector100 of FIG. 11.

While preferred embodiments of the present invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit or teachings of this invention. Theembodiments described herein are exemplary only and are not limiting.The particular features of the embodiments described above are exemplaryof the invention and may be useful with different embodiments notnecessarily having all of the same features. For example, the base 56 ofthe protector 50 of the embodiment of FIG. 2 may be formed with basetear starters 259 (FIG. 13) and the elongated bumper 262 of theembodiment of FIG. 14 may be formed with cut-outs 72 (FIG. 5). Manyvariations and modifications are possible and are within the scope ofthe invention. Accordingly, the scope of protection is not limited tothe embodiments described herein.

We claim:
 1. A protector for protecting the end of a pipe, comprising: abody; said body having a connector to connect with the pipe; said bodyhaving a bumper; said bumper having a configuration and being made of asubstantially non-metallic material; and said configuration and materialbeing capable of dissipating 1200 ft/lbs of energy at ambient and at150° F.
 2. A protector for protecting the end of a pipe, comprising: abody; said body having a connector to connect with the end of the pipe;and said body having a bumper having a solid annular configuration, saidbumper extending from the end of the pipe with at least one channelextending therearound.
 3. A protector for protecting the end of a pipe,comprising: a body; said body having a connector to connect with thepipe; and said body having a solid annular configuration with at leastone channel extending therearound, wherein said configuration andmaterial are capable of dissipating 1200 ft/lbs of energy at ambienttemperature and at 150° F.
 4. A protector for protecting the end of apipe, comprising: a body; said body having a connector to connect withthe pipe; said body having a bumper; said bumper having a solid annularconfiguration and a thickness; and said bumper having at least onechannel formed into said annular configuration and extending partiallyinto said thickness, said at least one channel being capable ofdissipating energy.
 5. A protector for protecting the end of a pipe,comprising: a body; said body having a connector to connect with thepipe; said body having a bumper; said bumper having a solid annularconfiguration and a thickness; said bumper having at least one channelformed into said annular configuration and extending partially into saidthickness; and inner and outer annular elongated ring shaped portionsextending axially from said bumper.
 6. A protector for protecting theend of a pipe, comprising: a body; said body having a connector toconnect with the pipe; said body having a bumper; said bumper having asolid annular configuration and a terminal end; said bumper including atleast one elongated ring shaped portion extending axially from saidterminal end.
 7. The protector of claim 6 comprising inner and outerannular elongated ring shaped portions extending axially from saidbumper, said outer portion being at a greater radius from the center ofthe protector than said inner portion.
 8. The protector of claim 7wherein said inner and outer annular elongated ring shaped portions havedifferent lengths.
 9. The protector of claim 8 wherein said outerelongated ring shaped portion has a length greater than the length ofsaid inner elongated ring shaped portion.
 10. A protector for protectingthe end of a pipe, comprising: a body; said body having a connector toconnect with the pipe, said connector having a wall with a thickness;said body having a bumper; said bumper having a configuration with asolid annular portion extending axially a distance greater than saidwall thickness and being made of a substantially non-metallic material;and said bumper having at least one channel extending there around. 11.A protector for protecting end of a pipe, comprising: a body; said bodyhaving a bumper having a distal end; and said bumper having a solidelongated annular configuration with at least one channel extendingabout said configuration, said at least one channel being locatedbetween said distal end and the end of the pipe.
 12. A protector forprotecting end of a pipe, comprising: a body having outer surface; abumper extending axially from said body; at least one channel formedinto said outer surface proximate said bumper.
 13. The protector ofclaim 12, wherein said bumper has an elongated annular configuration.14. The protector of claim 12, wherein said channel is capable ofminimizing the transmission of impact energy to the pipe.
 15. Theprotector of claim 12, wherein said body is constructed of a materialhaving the izod impact strength and the compressive properties of HHM5502.
 16. The protector of claim 12, wherein said channel minimizes thetransmission of impact energy by failing.
 17. The protector of claim 12,wherein said channel minimizes the transmission of impact energy bycracking.
 18. A protector for protecting the end of a pipe, comprising:a base having first and second ends, a thickness, and a circumference; apin extending axially from said first end of said base; an elongatedannular bumper extending axially from said second end of said base; andat least one annular channel around said circumference and extendingpartially into said thickness.
 19. The protector of claim 18, whereinsaid bumper and said at least one annular channel are capable ofcollectively dissipating 1200 ft/lbs of energy at ambient temperatureand at 150° F.
 20. The protector of claim 18, wherein said base and saidbumper are constructed of a material that plastically deforms under animpact.
 21. A protector of claim 18, wherein said base and said bumperare constructed of a material that transforms impact energy intointernal friction and thermal energy.
 22. The protector of claim 18,wherein said at least one annular channel is proximate to said elongatedannular bumper.
 23. A thread protector, comprising: a base; a boxextending axially from said base in a first direction, said box havingan internal bore and having an end; a bumper extending axially from saidbase in a second direction, said second direction being opposite saidfirst direction; and said bore having a first annular recess.
 24. Theprotector of claim 23, wherein said box comprising a plurality of threadmembers formed at least partially thereon, said first annular recessbeing adjacent said plurality of thread members closest to said base.25. The protector of claim 23, wherein said plurality of thread membershave a height wherein said first annular recess has a depthapproximately equal to said height.
 26. The protector of claim 23,wherein said bore further has a second annular recess, second annularrecess being adjacent to said plurality of thread members closest tosaid end of box.
 27. The protector of claim 23, wherein said bumper is asolid elongated annular bumper.
 28. A protector for protecting an end ofa pipe, comprising: a base having first and second ends and an outersurface; a box extending axially from said first end; a bumper extendingaxially from said second end; at least one annular channel formed intosaid base, said at least one channel capable of absorbing impact energy.29. The protector of claim 27, wherein said bumper comprises at leasttwo bumper arms.
 30. The protector of claim 28, wherein said at leasttwo bumper arms comprise annular outer and inner elongated ring shapedportions.